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TextFilePreview.javaAPI DocExample2382Tue Feb 14 13:49:34 GMT 2006None

TextFilePreview

public class TextFilePreview extends JTextArea implements PropertyChangeListener

(Omit source code)

Fields Summary
private File
selectedFile
private String
preview
private int
previewLength
Constructors Summary
public TextFilePreview(JFileChooser fc)

  
     
    super(10, 20);
    this.setEditable(false);
    this.setPreferredSize(new Dimension(150, 150));
    this.setLineWrap(true);
    fc.addPropertyChangeListener(this);
Methods Summary
private voidloadText()


    if (selectedFile != null) {
      try {
        FileInputStream fin = new FileInputStream(selectedFile);
        byte[] data = new byte[previewLength];
        int bytesRead = 0;
        for (int i = 0; i < previewLength; i++) {
          int b = fin.read();
          if (b == -1) break;
          bytesRead++;
          data[i] = (byte) b;
        }
        preview = new String(data, 0, bytesRead);
        fin.close();
      }
      catch (IOException ex) {
        // File preview is not an essential operation so 
        // we'll simply ignore the exception and return.
      }
    }
public static voidmain(java.lang.String[] args)

    
    SwingUtilities.invokeAndWait(
      new Runnable() {
        public void run() {
          JFileChooser fc = new JFileChooser();
          fc.setAccessory(new TextFilePreview(fc));
          int result = fc.showOpenDialog(new JFrame());
          if (result == JFileChooser.APPROVE_OPTION) {
            try {
              File f = fc.getSelectedFile();
              if (f != null) {
                InputStream in = new FileInputStream(f);
                for (int c = in.read(); c != -1; c = in.read()) {
                   System.out.write(c);
                }
                in.close();
              }
            }
            catch (IOException ex) {System.err.println(ex);}
          }
          System.exit(0);
        }  // end run
      } // end Runnable
    ); // end invokeAndWait
public voidpropertyChange(java.beans.PropertyChangeEvent evt)

  
    if (evt.getPropertyName().equals(
     JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)) {
      selectedFile = (File) evt.getNewValue();
      if(isShowing()) {
        loadText();
        this.setText(preview);
      }
    }